Thread-loop-cutting device



Feb, 24-, 1931. w. MYERS 31,793,5fig

THREAD LOOP CUTTING DEVICE v Filed Oct. 25, 1929 2 SheetsSheet l gmmntom' Walzer @ers WLWveoaey Feb. 24, 1931. w MYERS THREAD LOOP CUTTING DEVICE m Filed Oct. 25, 1929 2 Sheets-Sheet Patented Feb. 24, 1931 UNITED STATES PATENT OFFICE WALTER MYERS, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE SINGER MANU- FACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY THREAD-LOOP-GUTTING DEVICE Application filed October 25, 1929. Serial No. 402,377.

This invention relates to improvements in thread-cutting devices employed for cutting open the thread-loops successively formed to project from one face of a base-fabric by means of an organized sewing machine or turfing and the like implement, more particularly in the production of pile-fabric or pileembroidery effects.

The primary object of the present invention is to prpvide improved means, effective in the loop-forming operation, for successively cutting open the thread-loops in a manner such that the separated loop-limbs are of substantially equal length. A further 0b 1 ject of the invention is to provide a device for severing the thread-loops at the meeting point of the loop-limbs, i. e., at the middle of the loop-bights, in an organized sewing ma chine having a universal feeding mechanism.

Other and more specific objects of the invention will be apparent from the following description and claims.

A preferred form of the present improvement has been embodied in a commercially well known type of universal feed embroiderinimachine, in which the sewing thread is laid y a looper into the hook of a work-penetrating needle and is drawn through the work in the form of a loop in the 'roduction of chain stitches, or optionally o the so-called drop-stiches dependent upon the selected position of the needle and looper with respect to the direction of feed. In this universalfeed type of sewing machines, the work is usually advanced by an upper, four-motion feeding-foot of which the work-engaging movements alternate with those of a stripper-foot functioning to firmly hold the work during the retracting or loop-forming movement of the hook-needle. The feeding-foot may be manually or automatically controlled to change the direction of feed, the stitch-forming implements automatically maintaining a definite stitch-forming position with respect to the direction of feed of the work.

According to the present improvement, the stripper-foot is constructed to present an open needle-groove and the hook-needle is slabbed by cuttin away one side thereof to 50 provide a flat sur ace disposed substantially in the plane of the opposite edges of the stripper-foot groove. Adjustably mounted upon the stripper-foot is a bracket carrying a cutter-disk frictionally held against the flat side of theneedle and presentingacutting edge traversed by the needle-hook. Consequently, during the loop-forming movement of the needle, the needle-hook carries the threadloop against the cutting edge of the disk, the thread-loop being thereby cut open substantially at the middle of the loop-bight. The length of the loop at cutting position may be varied by adjustment of the height of thecutting-disk from the work-support.

Inasmuch as the slabbed needle and the stripper-foot with its thread-cutting disk maintain a fixed relationship with respect to the direction of feed, it is evident that the present thread-cutting device uniformly performs its function of cutting open successively formed thread-loops in the relatively same position of the loops, regardless of the direction of feed. It. is furthermore noted that when the stitch-forming mechanism is adjusted, in the usual manner, to make either chain or drop-stitches, the stripper-foot may be reversed in its carrier to accommodate the correspondingly changed needle-position. Accordingly the present thread-cutting device functions equally well regardless of whether the machine is set to make chainor drop-stitches.

In the accompanying drawings, Fig. 1 is a front side view in elevation and partly in section of a portion of a universal feed sewing machine in which the present improvement has been embodied. Fig. 2 comprises perspective views of the slabbed end of the needle, the strip er-foot and the cutter-disk with its carrying racket, said parts being shown in detached relationship. Fig. 3 is a perspective View of the hook end of the needle and illustrates the thread-clearance groove in the round side of the needle between the needlepoint and the needle-hook. Fig. 4 is a sectional view substantially on the line 4- of Fig. 5. Fig. 5 is a detail view in elevation and partly in section of the stitch-form ng and thread-cutter elements, in the threadreceiving position of the needle. Fig. 6 is a view similar to Fig. 5, but with the needle in thread-loop cutting position. The present improvement has been embodied in a universal-feed sewing machine constructed substantially in accordancewith the disclosure in my prior patent application filed Jan. 26, 1928, with Serial No. 249,506. Referring to the drawings in the present case, this sewing machine is constructed with a bed-plate 1 and a bracket-arm 2 overhanging the bed-plate, the bracket-arm terminating in a head 3, to which is suitably secured a needleand feed-supporting frame 4.

Journaled in the bracket-arm 2 is a rotary shaft 5, the operation of which is manually controllable from a hand-crank 6, upon the bracket-arm 2, through connections with a suitable stop-motion device (not shown). @peratively connected with the forward end of the shaft 5 is the driver 7 of a short, hollow needle-bar 8 splined for vertical reciprocation within the upper end of a cylinder 9 journaled for rotation about a vertical axis in suitable bearings provided in the supporting frame 4. Secured within the needle-bar 8 by a set-screw 10 is the shank 11 of a needle which, therefore, reciprocates vertically within the cylinder 9 butpartakes of any rotary movements of said cylinder. Fixed upon the cylinder 9 is a bevel-gear 12 in mesh with a similar gear 13 upon the forward end of the usual feed-direction controlling shaft 14 rotatable by operation of the hand-crank 6.

The feeding mechanism includes a feedingfoot or -ring 15 carried by a feed-bar 16 supported at its upper end, in the usual manner for universal movement about transverse axes in a manner to permit the feed direction to change upon rotation of the cylinder 9 by the provided with a throat-plate having a hand-crank 6. The feeding-foot derives its work-feeding movements from the shaft 5 in a manner so well known that it is deemed unnecessary to herein describe the actuating mechanism therefor in detail. For a more complete disclosure, reference may be had to my aforesaid pending application Serial No. 249,506, as well as to my prior Patent No. 1,325,033, Dec. 16, 1919. It will be observed, however, that in the present instance the work-engaging portion of the feedingfoot eomprises a ring of rubber or equivalent material 17 embedded in a grooved seat 18 provided in the bottom of the foot 15.

The work is supported at the stitching point by a plate 19, carried by the bed-plate 1 and needle-aperture 21. Below the throat-plate is the usual thread-positioning looper 22 carried by the vertically disposed looper-shaft 23 having a spiral-gear 24 engaged by a drivmg-gear 25. The spiral driving-gear 25 is carried by the forward end of'a rotary and endwise reciprocatory shaft 26 journaled in suitable hearings in the bed-plate 1, said driving-gear 25 being locked upon the shaft 26 masses in either one of two positions which may be selected to efiect the production of either chainor drop-stitches. The endwise reciprocatory movements of the shaft 26 impart oscillatory thread-positioning movements to the looper 22, while the rotary movements of said shaft maintain the looper position in correspondence with the needle position in dif; ferent directions of feed of the work. The actuating mechanism for the shaft 26 may be of any usual character, although preferably constructed as disclosed in my before mentioned patent application Serial No.

inder 9, the sleeve being suitably splined to said cylinder to permit of endwise reciprocation of the sleeve with respect to the cylinder and to partake of any rotary movements of the latter. At its upper end, the sleeve 27 carries a grooved collar 30 embraced by a forked arm 31 extending laterally from a lifting bar 32 depriving vertically reciprocatory movements from the shaft 5 in the usual manner.

Reversibly secured by a screw 33 within the lower portion of the sleeve-aperture 29 is the round, hollow shank 34 of a specially constructed stripper-foot 35, its'shank having a shoulder 36 engaging the underside of the sleeve 27. Below itsshouldered shank, the stripper-foot is partly cut away intermediate its ends and substantially centrally of the vertical needle-aperture 37 in the foot, whereby a portion of the length of said aperture 37 is converted into a substantially semicircular needle-groove 38. Extending laterally from the stripper-foot 35 is an car 39 having its opposite faces flattened and substantially parallel, one of said faces, as '40, being disposed in the vertical plane containing the opposite edges of the needle-groove 38. The opposite face 41 of the ear 39 alfords a seat for a suitably recessed, knife-carrying bracket 42 which is adjustably secured upon the stripper-foot by a screw 43 passing through a vertically elongated slot 44 in the car 39.

Carried by the bracket 42 is a disk-knife 45 extends across the stripper-foot groove 38 and preferably is in contact with the opposite edges of said groove. The lower end of the stripper-foot terminates in the usual needleembracing nipple 50.

The shank 11 of the needle is reduced at its lower end to provide a blade 51 which is cut away or slabbed at one side to provide a flat surface 52 substantially diametrical of the needle. Above its point, the needle is provided with a thread-loop receiving hook 53, the flat surface 52 extending past the needle-hook and to the needle-point. Below the needle-hook 53, the needle is provided the work-plate 19 below the feeding-foot 15 andthe stripper-foot nipple 50 in the raised position of the needle,-and a thread B has been inserted in the looper 22, the stitchforming and work-feeding mechanisms are brought into operation by manipulation of the hand-crank 6 to release the stop-motion device in the usual manner. The needle penetrates the base-fabric A and the looper 0seillates to lay the thread B in the needle-hook as shown in Fig. 5 of the drawings. In its rising movement, the needle draws up ,the'

thread in the form of a loop comprising looplimbs B" and B During the loop-forming or rising movement of the needle, the fabric is stripped therefrom by the stripper-foot nipple 50, which during this time is depressed into its work-engaging position. The

Y necessary clearance for the loop-limbs, during the passage of the needle-hook through the nipple 50, is provided at one side by the thread-clearance groove 54 in the needle and at the other side by the flattened face of the needle. As the needle rises above the nipple portion 50 of the stripper-foot, it carries the bight of the thread-loop against the cuttingedge of the disk-knife 45', thereby cutting the loop open at a point such that the separated loop-limbs B and B are of substantially equal length. When the active portion of the disk-knife edge becomes dulled by use, the resulting wedge-action upon the disk by the thread-loop in the rising movement of the needle is suflicicnt to overcome the frictional disk-holding means afforded by the frictionwasher 49, so that the disk is slightly rotated about the screw-bolt 46 and thereby a fresh cutting edge isv automaticallypresented to the thread-loops formed by the needle. Obviously the repositioning of the disk-knife might be manually effected, if desired.

It will therefore be understood that the thread-cutting device successively severs the thread-loops as they are formed and that the separated loop-limbs are of substantially equal length in any selected vertically adjusted position of the disk-knife. It is furthermore evident that the relative position of the disk-knife and needle is maintained, regardless of the direction of fed of the work, because the knife and the needle follow an rotation of the cylinder 9 to change the fee direction.

Having thus set forth the nature of the invention, what I claim herein is:

1. A sewing machine having a work-penetrating needle adapted to carry loops of thread through the work by engaging the bight of the thread-loops, means for actuat ing said needle, work-feeding means, and means positioned to cut open successively formed thread-loops substantially at the middle of the loop-bight while said loop-bight is held by the needle.

2. In a sewing machine, a work-penetrating needle, a looper actuated to present a thread to said needle,means for actuating said needle to carry a loop of said thread through the work with the needle engaging the thread-loop bight, and a thread-cutter positioned to coact with the needle in successive loop-forming movements to cut open each of the thread-loops substantially at the middle of the loop-bight while said loopbight is held by the needle.

3. A sewing machine having a reciprocatory work-penetrating needle adapted to carry a loop of thread through the work, means for feeding thework between successively formed thread-loops, and a thread-cutter having a cutting edge slidingly engaged by said needle during each loop-forming reciprocation thereof to cut open the successively formed thread-loops.

4. A sewing machine having a work-penetrating, open-eye needle, a looper at one side of the work for laying a thread in the eye of said needle, means for reciprocating said needle to successively carry loops of said thread through the work, and a thread-cutter at the side of the work opposite to the looper side thereof coacting with said needle in cutting open the successively formed thread-loops at substantially the middle of each loop-bight.

5. In' a sewing machine, the combination with a universal work-feeding mechanism, and a work-penetrating needle maintaining a definite loop-forming position with respect to said feeding mechanism in different directions of feed of the work, of means for cutting open the thread-loops successively formed by the needle at-substantially the middle of each loop-bight.

6. In a sewing machine, .the combination with a universal work-feeding mechanism,

of athread-cutting device efiective to cut the sewing thread between each of the successive work-feeding movements of said mechanism, and means for supporting said thread-cutting device to maintain a constant position relatively to the direction of feed of the work in diiferent directions of feed.

7. A pile-fabric forming device comprising an open-eye needle reciprocable to carry loops of thread through a base-fabric, a threadcutter presenting a cutting-edge traversed by the thread-engaging eye of said reciprocatory needle, and means for supporting said thread-cutter in contact with the needle whereby the thread-loops are successively cut open in the bights thereof engaged by-the needle. I

8. A pile-fabric forming device comprising a needle reciprocable to carry loops of thread through a base-fabric, a thread-cutter presenting. a cutting-edge traversed by the thread-engaging portion of said reciprocatory-needle, whereby the thread-loops carried by the needle are successively cut open in the loop-bights, and adjustable means for repositioning said thread-cutting edge in the path of reciprocation of the needle to change the length of the loop-limbs separated.

9. A pile-fabric forming device comprising a needle reciprocable to carry loops of thread through a base-fabric, a thread-cutter having a portion of its cutting edgeitraversed by the needle in the path ofthe loop-bights carried by the needle insuccessive reciprocations thereof, and means for supporting said thread-cutter permitting repositioning of different portions of its cutting-edge in the path of the 'loop-bights.

10. A pile-fabric forming device comprising a needle reciprocable tocarry loops of thread through a base-fabric, a thread-cutting disk having a peripheral cutting-edge of which a, portion is disposed in the path of the loop-bights carried by the needle, and supporting means for said disk permitting circular adjustment thereof ,to present different' portionsbf its cutting edge in the path of the loop-bights carried by said needle.

11. A sewing machinehaving a work-support, a needle reciprocable to carry loops of thread through work upon said work-support, a stripper-foot opposed to the worksupport engaging the work adjacent the path of the needle,"a thread-cutter carried by said stripper-foot in position to present a cutting edge in the path of thread-loops carried by the needle, and means for feeding the work "past the needle between successive reciprocations thereof.

I aveasee movements alternating with the work-engaging movements of the feeding-foot, and

a thread-cutter carried by said stripper-foot having a cutting-edge disposed in the path of the thread-loops carried by said needle.

13. A sewing machine having a work-support, a slabbed needle reciprocable to carry loops of thread through work upon said work-support, means for feeding the work relationship of said elements with respect to the direction of feed of the work, a threadcutter, and means for supporting said thread cutter with its cutting edge disposed in the path of a loop of thread carried by the needle in any direction of feed of the work.

in testimony whereof, l have signed my name to this specification.

. WALTER MYERS.

1-2. A sewing machine having a work-supthe work-support, a stripper-foot opposed to the work-supporthaving work-engaging port, a needle reciprocable to carry loops of 

